1. Field of the Invention
The present invention relates to a substrate processing apparatus, a substrate support apparatus, a substrate processing method, and a substrate fabrication method and, more particularly, to a substrate processing apparatus, a substrate support apparatus, and a substrate processing method by which two substrates are overlapped and contacted, and a substrate fabrication method using any of these apparatuses and method.
2. Description of the Related Art
A method of contacting two wafers (substrates) and bonding the contacted wafers by, e.g., anodization, pressing, or heat treatment is suited to the fabrication of a wafer having an SOI structure or the like.
FIGS. 25A and 25B are schematic views showing a part of a process of bonding wafers. In this bonding process, as shown in FIG. 25A, a first wafer 1 is set on a wafer support jig 201 with the bonding surface of the first wafer 1 turned up, and a second wafer 2 is gently overlapped on the first wafer 1 with the bonding surface of the second wafer 2 turned down. In this state, as shown in FIG. 25A, the upper wafer 2 floats by the gas (e.g., air or inert gas) between the wafers.
Next, as shown in FIG. 25B, a press pin 202 presses the center and its vicinity of the upper wafer 2 before the gas between the wafers 1 and 2 is completely discharged. Consequently, air between the central portions of the wafers is pushed toward the periphery to first contact the central portions of the wafers 1 and 2. Thereafter, air between the wafers is gradually pushed toward the periphery to increase the area of the contact portion. Finally, the two wafers are entirely contacted.
This method is useful as a method of contacting two wafers by a simple jig and is also considered as a fundamental technique readily applicable to large-diameter wafers.
Generally, the in-plane uniformity of a wafer becomes difficult to ensure as the diameter of the wafer increases. The above method is expected to be able to solve the problem of this in-plane uniformity even when the method is applied to the fabrication of large-diameter wafers. However, a technique suited to larger diameters is being desired.
It is an object of the present invention to provide an apparatus and a method of easily contacting large-diameter substrates.
A substrate processing apparatus according to the present invention is a substrate processing apparatus for overlapping and contacting two substrates comprising a support unit for supporting a first substrate, and a press unit for pressing a second substrate opposed to the first substrate supported by the support unit, wherein the support unit can support the first substrate while a predetermined portion of the first substrate is so curved as to separate from the second substrate and is not curved.
In the above substrate processing apparatus, the press unit preferably presses a back surface of the second substrate opposed to the first substrate supported by the support unit.
In the above substrate processing apparatus, it is preferable that the support unit can support the first substrate while a peripheral portion of the first substrate is so curved as to separate from the second substrate and is not curved, and the press unit press a substantially central portion of the second substrate opposed to the first substrate supported by the support unit.
In the above substrate processing apparatus, it is preferable that the support unit support the first substrate in a curved state until a predetermined time elapses after the press unit starts pressing a back surface of the second substrate, and support the first substrate in an uncurved state thereafter.
In the above substrate processing apparatus, it is preferable that the support unit support the first substrate in a curved state until a contact portion of the first and second substrates spreads to a predetermined region after the press unit starts pressing a back surface of the second substrate, and support the first substrate in an uncurved state thereafter.
In the above substrate processing apparatus, the support unit preferably comprises an adjusting unit for adjusting the curve of the first substrate to spread a contact portion of the first and second substrates step by step from a center to a periphery thereof.
In the above substrate processing apparatus, the adjusting unit preferably adjusts the curve of the first substrate to spread the contact portion of the first and second substrates concentrically step by step.
In the above substrate processing apparatus, the support unit preferably comprises a chuck unit for curving the first substrate by chucking a back surface of the first substrate.
In the above substrate processing apparatus, it is preferable that the support unit comprises a support table having a peripheral portion lower than a central portion, and the support table chuck the first substrate.
In the above substrate processing apparatus, the support table preferably comprises a disk-like central portion and one or a plurality of annular peripheral portions.
In the above substrate processing apparatus, it is preferable that the support table comprises a disk-like central portion and an annular peripheral portion, and a chuck surface of the peripheral portion be inclined to a chuck surface of the central portion.
In the above substrate processing apparatus, a chuck surface of the central portion and a chuck surface of the peripheral portion preferably have chuck mechanisms for chucking the first substrate.
In the above substrate processing apparatus, it is preferable that frog-like pins for supporting the first substrate be formed on the chuck surfaces of the central portion and/or the peripheral portion, and the first substrate be chucked by evacuating a space between the pins.
In the above substrate processing apparatus, only a chuck surface of the peripheral portion of the support table preferably has a chuck mechanism for chucking the first substrate.
In the above substrate processing apparatus, the support table of the support unit preferably chucks only a periphery of the first substrate to separate a central portion of the first substrate from a central portion of the support table.
In the above substrate processing apparatus, it is preferable that the apparatus further comprises a substrate manipulation unit for supporting the second substrate with the second substrate opposing the first substrate supported by the support unit, and releasing the second substrate, and the press unit press the second substrate when the substrate manipulation unit releases the second substrate.
In the above substrate processing apparatus, it is preferable that the support unit substantially horizontally support the first substrate, and the substrate manipulation unit substantially horizontally support the second substrate above the first substrate and release the second substrate.
A substrate support apparatus according to the present invention is a substrate support apparatus for supporting one of two substrates when the two substrates are overlapped and contacted comprising a support unit capable of supporting the substrate in a curved state and an uncurved state.
In the above substrate support apparatus, the support unit preferably can support the substrate while a periphery of the substrate is curved and is not curved with respect to a central portion of the substrate.
In the above substrate support apparatus, the support unit preferably supports the substrate first in a curved state and then in an uncurved state.
In the above substrate support apparatus, the support unit preferably comprises an adjusting unit for adjusting the curve of the substrate to spread a contact portion of the supported substrate and the other substrate to be contacted to the substrate step by step from a center to a periphery thereof.
In the above substrate support apparatus, the adjusting unit preferably adjusts the curve of the supported substrate to spread the contact portion concentrically step by step.
In the above substrate support apparatus, the support unit preferably curves the substrate by chucking a back surface of the substrate.
In the above substrate support apparatus, it is preferable that the support unit comprises a support table having a peripheral portion lower than a central portion, and the support table chuck the first substrate.
In the above substrate support apparatus, the support table preferably comprises a disk-like central portion and one or a plurality of annular peripheral portions.
In the above substrate support apparatus, it is preferable that the support table comprises a disk-like central portion and an annular peripheral portion, and a chuck surface of the peripheral portion be inclined to a chuck surface of the central portion.
In the above substrate support apparatus, a chuck surface of the central portion and a chuck surface of the peripheral portion preferably have chuck mechanisms for chucking the substrate.
In the above substrate support apparatus, only a chuck surface of the peripheral surface of the support table preferably has a chuck mechanism for chucking the substrate.
In the above substrate support apparatus, the support table of the support unit preferably chucks only a periphery of the substrate to separate a central portion of the substrate from a central portion of the support table.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a periphery of the first substrate is so curved as to separate from a periphery of the second substrate, and setting the first substrate in an uncurved state after a predetermined time elapses.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a periphery of the first substrate is so curved as to separate from a periphery of the second substrate, and setting the first substrate in an uncurved state after a contact portion of the first and second substrates spreads to a predetermined region.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a periphery of the first substrate is so curved as to separate from a periphery of the second substrate, and adjusting the curve of the first substrate to spread a contact portion of the first and second substrates step by step from a center to a periphery thereof.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a periphery of the first substrate is so curved as to separate from a periphery of the second substrate, and adjusting the curve of the first substrate to spread a contact portion of the first and second substrates concentrically step by step from a center to a periphery thereof.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a predetermined portion of the first substrate is so curved as to separate from the second substrate, and setting the first substrate in an uncurved state after a predetermined time elapses.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a predetermined portion of the first substrate is so curved as to separate from the second substrate, and setting the first substrate in an uncurved state after a contact portion of the first and second substrates spreads to a. predetermined region.
A substrate processing method according to the present invention is a substrate processing method of overlapping and contacting two substrates comprising the steps of opposing first and second substrates to each other, pressing the second substrate while a predetermined portion of the first substrate is so curved as to separate from the second substrate, and adjusting the curve of the first substrate to spread a contact portion of the first and second substrates step by step from a center to a periphery thereof.
In each of the above substrate processing methods, a back surface of the second substrate is preferably pressed.
Further objects, features, and advantages of the present invention will become apparent from the following detailed description of embodiments of the present invention with reference to the accompanying chucks.